1. Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering Kansai University, 3‐3‐35 Yamate‐cho, Suita Osaka 564‐8680 Japan
2. Chemicals R and D Group, HPM Research and Development Department, High Performance Materials Company JXTG Nippon Oil and Energy Corporation, 8 Chidori‐cho, Naka‐ku Yokohama Kanagawa 231‐0815 Japan